Hi,

The smallest design features I want to create are 2.5 um channels made
by SU-8 25 resist (thickness about 10 um) on AF45 glass wafers.
I use near-UV lithography.
I can not open the channels during development (5 min. stirring ; mr-DEV
600 developer is used). 5 um channels are formed without any problem.

I know 2.5 um is close to the near-UV resolution limits, but is this
really a lithographic issue or maybe a development issue?

Can anybody help me?

Herman.